1. Field of the Invention
The present invention relates to a liquid-supply reservoir in a liquid-using machine, such as a diazo copying machine. The present invention is particularly directed to a liquid-supply reservoir in a copier. Typically, a liquid-supply reservoir has a closeable opening at the top in which there are detachably secured a pipe extending to near the base of the reservoir and a liquid-level sensing device.
2. Description of the Prior Art
U.S. Pat. No. 3,366,276 and British Patent No. 1,343,130 both describe liquid-supply reservoirs having a rigid pipe permanently secured therein which also acts as a guide means for a freely moveable float. This float is part of a liquid-level sensing means which entirely surrounds the rigid pipe. The pipe in British Patent No. 1,343,130 is completely sealed at the bottom whereas the pipe in U.S. Pat. No. 3,366,276 is provided with slots at the bottom such that the entire pipe acts as a liquid conduit. Neither pipe, however, can be removed thus preventing easy access to the reservoir.
British Patent Application No. 1,310,840 and Netherlands Patent Application No. 7,013,841 describe a liquid-supply reservoir provided with a top opening having a lid which fits thereon and which is provided with openings through which pass a liquid-level sensing device and pipes for introducing liquid into and taking liquid from the reservoir. The sensing device and pipes are separately secured to the lid. Similarly, German Auslegeschrift No. 1,655,517 describes a liquid-supply reservoir having a discharge pipe and a liquid-level sensor which are separately secured to a removeable lid of the reservoir.
As appears from British Patent No. 1,310,840 and German Auslegeschrift No. 1,655,517, at least the discharge pipe that is secured to the lid must be rigid and extend close to the base of the reservoir to enable the reservoir to be emptied. Upon replacement, the installed reservoir must be moved vertically downwards with respect to the lid for a distance which is at least equal to the maximum length by which the rigid pipe part, or the liquid-level sensing device, respectively, project into the reservoir. If the lid is secured to the reservoir by a screw connection, the reservoir will also have to be rotated to detach it from the lid.
A disadvantage of the above-described reservoir is that there must be a free space beneath the installed reservoir to enable the replacement movements of the reservoir to be carried out. During handling of the reservoir, liquid can easily be spilled. Another disadvantage is that the reservoir cannot rest on a fixed support. This is a distinct disadvantage when the reservoir is full and relatively heavy.
U.S. Pat. No. 3,698,454 and German Offenlegungschrift No. 3,402,506 both describe a liquid-supply reservoir wherein a rigid pipe used as a liquid conduit can be automatically inserted into or lifted out of the reservoir through a top opening. In addition to the complexity added by the automatic insertion and removal means, neither document has a liquid-level sensing device.
U.S. Pat. No. 3,817,274 describes a liquid-supply reservoir wherein a rigid pipe is secured in a support housing which fits into an opening at the top of the reservoir. It also has a float forming part of a liquid-level sensing device which entirely surrounds the rigid pipe and is freely moveable over almost the entire length of the pipe.
An object of this invention, therefore, is to provide a liquid-supply reservoir without the above disadvantages and to provide a liquid-supply reservoir which can easily be replaced.